Replacement heart valve

ABSTRACT

A replacement heart valve can have an expandable frame configured to engage a native valve annulus. A valve body can be mounted onto the expandable frame to provide functionality similar to a natural valve. The valve body has an upstream end and a downstream end, and a diameter at the downstream end is greater than a diameter at the upstream end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/165,721, filed Jun. 21, 2011, which claims priority to U.S.Provisional Application No. 61/357,048, which was filed on Jun. 21,2010. The entire contents of the above applications are herebyincorporated by reference herein. Further, Applicants' U.S. applicationSer. No. 12/569,856, filed Sep. 29, 2009, and U.S. application Ser. No.12/761,349, filed Apr. 15, 2010 disclose several embodiments ofreplacement heart valves. In some instances the present disclosuredescribes embodiments and principles that build upon and improveembodiments disclosed in these previous applications. As such, theentirety of each of these prior applications is incorporated byreference into this disclosure.

BACKGROUND Field of the Invention

The present invention relates generally to replacement heart valves.

Description of Related Art

Human heart valves, which include the aortic, pulmonary, mitral andtricuspid valves, function essentially as one-way valves operating insynchronization with the pumping heart. The valves allow blood to flowin a downstream direction, but block blood from flowing in an upstreamdirection. Diseased heart valves exhibit impairments such as narrowingof the valve or regurgitation. Such impairments reduce the heart'sblood-pumping efficiency and can be a debilitating and life threateningcondition. For example, valve insufficiency can lead to conditions suchas heart hypertrophy and dilation of the ventricle. Thus, extensiveefforts have been made to develop methods and apparatus to repair orreplace impaired heart valves.

Prostheses exist to correct problems associated with impaired heartvalves. For example, mechanical and tissue-based heart valve prosthesescan be used to replace impaired native heart valves. More recently,substantial effort has been dedicated to developing replacement heartvalves, particularly tissue-based replacement heart valves, that can bedelivered with less trauma to the patient than through open heartsurgery. Replacement valves are being designed to be delivered throughminimally invasive procedures and even percutaneous procedures. Suchreplacement valves often include a tissue-based valve body that isconnected to an expandable frame that is then delivered to the nativevalve's annulus.

Development of replacement heart valves that can be compacted fordelivery and then controllably expanded for controlled placement hasproven to be particularly challenging.

SUMMARY OF THE INVENTION

Accordingly, there is in the need of the art for an improved replacementheart valve.

In accordance with one embodiment, the present invention provides areplacement heart valve that comprises an expandable frame and a valvebody mounted onto the expandable frame. The expandable frame may have anengagement system configured to engage a native valve annulus at anengagement zone along the length of the frame. The frame can have anupstream portion, a downstream portion, and a transition portion betweenthe upstream and downstream portions, where a diameter of the downstreamportion is greater than a diameter of the upstream portion. The valvebody can have a plurality of valve leaflets configured to move betweenan open condition and a closed condition. A diameter of the valve bodyat a downstream end of the leaflets can be greater than a diameter ofthe valve body at an upstream end of the leaflets and the upstream endof each leaflet can be positioned upstream of the frame engagement zone.

In some embodiments, the engagement system comprises a set of upstreamanchors and a set of downstream anchors, each anchor comprising ananchor tip, and the frame engagement zone is defined between the tips ofthe upstream and downstream anchors.

The anchors can include one of many features. For example, a diameterdefined by the tips of the upstream anchors can be approximately equalto a diameter defined by the tips of the downstream anchors. As anotherexample, the downstream anchors can extend from the downstream portionof the expandable frame and the upstream anchors can extend from an areaof the frame having a diameter less than the downstream portion, such asthe upstream portion or the transition portion of the expandable frame.

In some embodiments, a replacement heart valve comprises an expandableframe configured to engage a native valve annulus at an engagement zonealong the length of the frame and a valve body attached to theexpandable frame. The expandable frame can include a foreshorteningportion configured to longitudinally contract as the frame radiallyexpands from a compacted to an expanded condition, a plurality of firstanchors and a plurality of second anchors.

Each of the anchors, according to some embodiments, can extend radiallyoutwardly from the frame at an anchor base and terminate at an anchortip. At least part of the foreshortening portion can be disposed betweenthe first and second anchor bases and the engagement zone can be definedbetween the first and second anchor tips. Further, the first anchors cancomprise first, second and third spaced apart bending stages along thelength of each upstream anchor, and wherein the first anchor is bentradially outwardly in the first and second bending stages, and is bentin an opposite direction in the third bending stage.

The anchors may include additional features. For example, the portion ofthe first anchor between the third bending stage and the anchor tip canbe generally parallel to an axis of the frame. The second anchor cancomprise first, second and third spaced apart bending stages, andwherein in the first bending stage the anchor is bent radially inwardly,in the second bending stage the anchor is bent radially outwardly, andin the third bending stage the anchor is bent radially inwardly. Thesecond bending stage of the first anchor can be bent about 180 degrees.

According to some embodiments, a replacement heart valve comprises anexpandable frame configured to engage a native valve annulus at anengagement zone along the length of the frame, and a valve body attachedto the expandable frame. The valve body can comprise a plurality ofvalve leaflets configured to open to allow flow in a first direction andengage one another so as to close and not allow flow in a seconddirection opposite the first direction. The expandable frame cancomprise an upstream portion, a downstream portion, a transitionportion, a plurality of upstream anchors and a plurality of downstreamanchors.

The downstream portion can have a diameter different than a diameter ofthe upstream portion. The transition portion can be between the upstreamand downstream portions. Each anchor can extend radially outwardly fromthe frame at an anchor base and terminate at an anchor tip. At leastpart of a foreshortening portion disposed between the upstream anddownstream anchor bases. The engagement zone defined between theupstream and downstream anchor tips. The bases of the upstream anchorscan be disposed at a location along the length of the frame having afirst diameter, and the bases of the downstream anchors can be disposedat a location along the length of the frame having a second diameter,and the first diameter is different than the second diameter.

In some embodiments, the diameter of the downstream portion is greaterthan the diameter of the upstream portion. In addition, in someembodiments, the bases of the upstream anchors are disposed in theupstream portion, and the bases of the downstream anchors are disposedin the downstream portion or the bases of the upstream anchors aredisposed in the transition portion, and the bases of the downstreamanchors are disposed in the downstream portion.

In some embodiments, a replacement heart valve comprises an expandableframe configured to engage a native valve annulus and a valve bodymounted onto the expandable frame. The valve body can comprise aplurality of valve leaflets configured to open to allow flow in a firstdirection and engage one another so as to close and not allow flow in asecond direction opposite the first direction. The valve body can havean upstream end and a downstream end where a diameter at the downstreamend is greater than a diameter at the upstream end.

In some embodiments, a replacement heart valve comprises an expandableframe configured to engage a native valve annulus and a valve bodymounted onto the expandable frame. The valve body can include aplurality of valve leaflets configured to open to allow flow in a firstdirection and engage one another so as to close and not allow flow in asecond direction opposite the first direction. The expandable frame canhave an upstream portion, a downstream portion, a first set of anchors,and a second set of anchors. A diameter of the expandable frame at thedownstream portion can be greater than a diameter of the expandableframe at the upstream portion. Further, each anchor can comprise ananchor tip. The first set of anchors can extend from the downstreamportion of the expandable frame and the second set of anchors can extendfrom an area of the frame having a diameter less than the downstreamportion. The anchor tips of the first set of anchors can be configuredto be positioned generally opposed to the anchor tips of the second setof anchors when the expandable frame is engaged to the native valveannulus.

Other inventive embodiments and features are disclosed below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages are described belowwith reference to the drawings, which are intended to illustrate but notto limit the invention. In the drawings, like reference charactersdenote corresponding features consistently throughout similarembodiments.

FIG. 1 is a perspective view of one embodiment of a replacement heartvalve.

FIG. 2 is a view looking upstream through the replacement heart valve ofFIG. 1.

FIGS. 3A and 3B are schematic views of one embodiment of a valve body.

FIG. 4 is a schematic side view of one embodiment of a frame forsupporting a valve body.

FIG. 5 is a partial flat pattern depiction of the pattern from which theframe of FIG. 4 is cut.

FIGS. 6 and 6A show valve leaflets configured in accordance with oneembodiment.

FIG. 7 illustrates components of an outer valve skirt configured inaccordance with one embodiment.

FIG. 8 illustrates components of another embodiment of an outer valveskirt.

FIG. 9 illustrates components of still another embodiment of an outervalve skirt.

FIG. 10 shows an embodiment of a connection skirt.

FIG. 11 is a schematic side view of another embodiment of a frame.

FIG. 12 is a partial flat pattern depiction of the pattern from whichthe frame of FIG. 11 is cut.

FIG. 13 is a side view of still another embodiment of a frame.

FIG. 14 shows a schematic side view of yet another embodiment of aframe.

FIGS. 15-19 are photographs filed in U.S. Provisional Application No.61/357,048, filed on Jun. 21, 2010, which has been incorporated hereinby reference. FIG. 15 is an image, from the perspective of the leftventricle, of one embodiment of a replacement heart valve positionedwithin a native mitral valve.

FIG. 16 is another image, from the perspective of the left ventricle, ofthe replacement heart valve of FIG. 15 positioned within a native mitralvalve.

FIG. 17 is another image, from the perspective of the left ventricle, ofthe replacement heart valve of FIG. 15 positioned within a native mitralvalve.

FIG. 18 is an image, from the perspective of the left atrium, of thereplacement heart valve of FIG. 15 positioned within a native mitralvalve.

FIG. 19 is an image, from the perspective of the left atrium, of thereplacement heart valve of FIG. 15 positioned within a native mitralvalve.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present specification and drawings disclose aspects and features ofthe invention in the context of several embodiments of replacement heartvalves and portions thereof that are configured for replacement ofnatural heart valves in a patient. These embodiments may be discussed inconnection with replacing specific valves such as the patient's aorticor mitral valve. However, it is to be understood that the context of aparticular valve or particular features of a valve should not be takenas limiting, and features of any one embodiment discussed herein can becombined with features of other embodiments as desired and whenappropriate.

With initial reference to FIGS. 1 and 2, an embodiment of a replacementheart valve 10 is shown. The illustrated replacement heart valve 10 isdesigned to replace a diseased native mitral valve. In this embodiment,the replacement heart valve 10 is made up of a self-expanding frame 20to which a valve body 30 is attached. As best seen in FIG. 2, the valvebody 30 includes flexible leaflets 32 that open and close. The valvebody 30 can include two, three or more leaflets 32. The valve body 30has an inflow end 34 and an outflow end 36. The replacement heart valve10 is shown with an upstream portion 38, a transition portion 40adjacent the upstream portion 38 and a downstream portion 42 disposedadjacent the other side of the transition portion 40.

The valve body 30 can extend the length of the frame 20 or it can extendalong only part of the length of the frame 20. For example, the valvebody 30 shown in FIGS. 1 and 2 extends along the upstream portion 38 andthe transition portion 40. The valve body 30 also extends along thenon-foreshortening zone 52. In another embodiment the valve body 30 alsoextends along the downstream portion 42 and/or the foreshortening zone54. As shown, in the illustrated embodiment a connection skirt 50extends along the length of the downstream portion 42. In someembodiments, the ends 14, 16 of the replacement heart valve 10 cancoincide with the inflow end 34 of the valve body 30 and the outflow end36 of the valve body. In the illustrated embodiment, the inflow end 34substantially coincides with one end 14 of the replacement heart valve10 while the other end 16 of the replacement heart valve 10 extends pastthe outflow end 36 of the valve body.

The valve body 30 can be implanted within a heart to replace a damagedor diseased heart valve such as a mitral valve. The valve leaflets 32can function in a manner similar to the natural mitral valve. Forexample, a plurality of valve leaflets 32 can open to allow flow in afirst direction and engage one another so as to close and not allow flowin a second direction opposite the first direction. The replacementheart valve 10 can be constructed so as the open naturally with thebeating of the heart.

Additional example replacement heart valves with valve bodies andleaflets are discussed in detail in Applicants' U.S. application Ser.No. 12/569,856, filed Sep. 29, 2009, incorporated by reference herein inits entirety and with particular reference to FIGS. 1-3C, 5-13 and 17-25and the accompanying discussion including paragraphs [0063]-[0070],[0083]-[0101], [0110]-[0114], [0118], [0124]-[0128], and [0130]-[0137].

With continued reference to FIGS. 1-2, in this embodiment, the frame 20is elongate with different diameter sections. For example, the upstreamend 14 of replacement heart valve 10 or frame 20 has a first diameterthat is substantially less than a second diameter at the downstream end16. The frame 20 maintains the first diameter along its length in theupstream portion 38. In the transition portion 40 between the upstream38 and downstream 42 portions, the frame 20 flares outwardly so that thediameter increases to the second diameter. The downstream portion 42disposed adjacent the transition portion 40 preferably maintains thesecond diameter along its length.

The frame 20 is constructed from a metal tube, such as a nitinol tube.As such, the frame 20 can be expanded and/or compressed and/or otherwiseworked to have the desired introduction and implantation configurations.

The frame 20 is constructed so that part of the frame foreshortens asthe frame is radially expanded from a collapsed configuration. In theillustrated embodiment a foreshortening zone 54 generally correspondswith the downstream portion 42. A non-foreshortening zone 52 extendsupstream from the foreshortening zone 54, and generally corresponds tothe upstream 38 and transition 40 portions.

Opposing anchors 22, 24 are constructed on the frame 20 so thatpreferably their tips 26, 28 are in the downstream portion 42. Theanchors 22, 24 are configured to grasp opposite sides of the nativemitral annulus. In some embodiments, one or more of the anchor tips 26,28 are in the downstream portion 42, the upstream portion 38, thetransition portion 40, or at or near the border of the transitionportion 40 and the downstream portion 42 or the border of the transitionportion 40 and the upstream portion 38. Preferably, each of the anchors22, 24 also extends generally radially outwardly from the frame 20 sothat the anchor tips 26, 28 are generally spaced away from the rest ofthe frame 20. In some embodiments, all or part of the structureconnected to the anchor tip and extending radially from the frame,including one or more rings and/or struts, can be considered part of theanchor. The anchors can include a base located on the anchor on a sideopposite the tip. The base can be for example where the anchor begins toextend away from the frame 20.

As shown, the anchors 22 extend from the downstream portion 42 of theframe 20. For example, the anchors 22 can extend from the end 16 of theframe 20. In some embodiments the anchors 22 can extend from other partsof the downstream portion 42 of the frame. The illustrated anchors 24extend from the upstream portion 38 of the frame 20. As such, theanchors 24 and the anchors 22 both extend from regions having differentdiameters. As an additional example, the anchors 24 can extend from thedownstream portion 42 and the anchors 22 can extend from the transitionportion 40. Alternatively, both set of anchors 22, 24 can extend fromthe transition portion 40.

The anchors 22, 24 can also extend from regions having the samediameter. For example both sets of anchors can extend from thedownstream portion 42.

The anchors 22, 24 can be one of many different lengths. For example,the anchors can be shorter than, as long as or longer than any of theupstream 38, transition 40, and downstream 42 portions. As shown, theanchors 24 are shorter than the downstream portion 42 and the anchors 22are longer than the transition portion 40. The anchors 22 extend fromthe upstream portion 38, through the transition portion 40 and into thedownstream portion 42. Other configurations are also possible.

The anchor tips 26, 28 can have one of many shapes. For example, theshape can be configured to increase the amount of surface area of thetip that is in contact with tissue. The tips 26, 28 are shown as roundor elliptical disks but can have other shapes as well, such as teardrop, rectangular, rectangular with a curved end, etc.

In preferred embodiments, the replacement heart valve 10 may be deployedinto a heart valve annulus, and positioned when compacted so that theanchor tips 26, 28 of the opposing anchors 22, 24 are disposed onopposite sides of the native annulus. As the replacement heart valve 10is expanded, the opposing anchors are drawn closer together so as tograsp opposite sides of the native annulus with the anchor tips 26, 28and securely hold the replacement heart valve 10 in position. As such,the replacement heart valve 10 can be held securely in position withoutrequiring a substantial radial force against the native annulus. Theforeshortening zone 54 can be used to move the anchor tips 26, 28 closertogether as the replacement heart valve 10 moves to the expandedposition to thereby engage the native valve annulus.

Applicant's U.S. patent application Ser. No. 12/084,586, which waspublished on Aug. 27, 2009 as U.S. Publication No. 2009/0216314,discusses embodiments of foreshortening stents with anchors, and can bereferred to for further discussion of certain aspects of the illustratedembodiments. The above application is incorporated in its entirety byreference herein with particular reference to the discussion concerningstructure and operation of embodiments of a foreshortening stent,particularly a foreshortening stent having anchors.

FIGS. 3A-B show an embodiment of the valve body 30 separate from theother components of the replacement heart valve 10. The valve body 30preferably is shaped to accommodate the transition portion 40 of theframe 20. More specifically, the valve body transition portion 40 isgenerally conical, where the upstream portion 38 is generallycylindrical. In embodiments where the valve body 30 extends into thedownstream portion 42, the downstream portion can also be generallycylindrical. In some embodiments, one or more of the upstream portion 38and the downstream portion 42 can be generally conical. In theillustrated embodiment, the upstream portion 38 of the valve body 30 hasan inflow diameter D₁. A downstream, or outflow end 36 of the valve body30 has a diameter D₂ that is greater than the upstream portion diameterD₁. Approaching the outflow end 36 of the valve body 30, the valve bodyflares outwardly to the larger diameter. As such, the inflow diameter D₁of the valve body 30 is less than the outflow diameter D₂ of the valvebody 30. The inflow D₁ and outflow D₂ diameters can vary greatly, insome embodiments, the inflow diameter D₁ can be approximately 30 mm andthe outflow diameter D₂ can be approximately 40 mm.

The valve leaflets 32 extend along all or part of the length of thevalve body 30, and including all or part of the reduced and increasingdiameter portions of the valve body, i.e. the upstream 38 and transition40 portions, as shown. In some embodiments, the leaflets 32 can alsospan all or part of the length of the downstream portion 42.

As best shown in FIGS. 1 and 2, the replacement heart valve 10 can alsoinclude a connection skirt 50. The connection skirt 50 can be a flexiblefabric, preferably a knit polyester fabric. The connection skirt 50 canbe attached to one or both of the frame 20 and the valve body 30. Asshown, the connection skirt 50 is attached to the distal end of thevalve body 30 and also attached to the frame 20 in the foreshorteningzone. In the illustrated embodiment, the valve body 30 is attached tothe frame 20 so that it is contained within the non-foreshortening zone.In other embodiments, the valve body 30 may be partially contained inboth the non-foreshortening zone 52 and the foreshortening zone 54. Someembodiments may not include the connection skirt 50.

With additional reference to FIGS. 4 and 5, a schematic side view of theframe 20 is shown, along with a flat pattern depiction of the patternfrom which the frame 20 is cut from a metal tube, such as a nitinoltube. As mentioned previously, the frame 20 has a non-foreshorteningzone 52 and a foreshortening zone 54. As shown, longitudinal struts 56span the length of the non-foreshortening zone 52. Distal or downstreamportions of the longitudinal struts 56 make up the transition portion40, in which the struts 56 bend so as to flare radially outwardly andthen bend again so as to stop expanding in radius and attach to theforeshortening zone 54 of the frame 20. As such, the frame 20 isgenerally divided into an upstream portion 38 made up of the firstdiameter, a transition portion 40 at which the diameter is expanding,and a downstream portion 42 which includes the foreshortening zone 54and which is adapted to engage the native valve annulus.

First 58, second 60, and third 62 rings made up of undulating struts areconnected to the longitudinal struts 56 in the non-foreshortening zone52. The illustrated first 58 and second 60 rings are of generally thesame size, however, the struts in the third ring 62 are substantiallylarger and longer than the struts in the first 58 and second 60 rings.For example, the struts of the first 58 and second 60 rings can be abouttwice as long as the struts of the third ring 62, or longer.Additionally, upstream anchors 22 extend from the free apices of thestruts in the third ring 62. As best shown in FIG. 4, the struts in thethird ring 62 preferably are flared radially out at a more dramaticangle than is the longitudinal strut 56 at the transition portion 40. Inthe illustrated embodiment, the third ring struts 62 can be consideredpart of the upstream anchors 22.

Referring to FIGS. 4 and 5, a fourth ring 64 is attached to the distalend of the longitudinal struts 56 at an apex of the fourth ring 64. Afifth ring 66 attaches to the fourth ring 66 on the side opposite thelongitudinal struts 56. The fifth ring 66 can be a mirror image of thefourth ring 64. As illustrated, the fourth 64 and fifth 66 rings are ofgenerally the same size. The fourth 64 and fifth 66 rings are made up ofundulating struts and make up the foreshortening zone 54. Expansion ofthe replacement heart valve 10 causes the struts of the fourth ring 64to move farther apart such that they are at a greater angle relative toone another. Thus, they move from a relatively vertical orientation to amore horizontal orientation. This also causes the ring to shrink invertical height. The fifth ring exhibits similar behavior when the valve10 expands. This movement of the fourth 64 and fifth 66 rings results inforeshortening of the frame 20.

Additionally, downstream anchors 24 extend from the free apices of thefifth ring 66. As best shown in FIG. 4, the downstream anchors 24 arebent down and flared radially out from the struts of the fourth 64 andfifth 66 rings. The upstream anchors 22 on the third ring 62 are bent soas to generally oppose the downstream anchors 24 that extend from theforeshortening zone 54. A tip 26 of each upstream anchor 22 isdownstream of the transition portion 40. As such, the downstream anchors24 extend from the distal or outflow end 16 of the valve 10, and theupstream anchors 22 extend outwardly from the upstream portion of thevalve 10, upstream of the transition portion 40.

The shape of each of the anchors will now be described in more detailwith reference to FIG. 4. Each anchor 22, 24 can have one or morebending stages to position the anchor tip in the desired location.Preferably, each anchor has at least two bending stages.

The downstream anchor 24 has a base 76 that is connected to a free apexof the fifth ring 66. After the base 76 there is a first bending stage78 so that the anchor is radially spaced outwardly from the frame 20. Asshown, the anchor at the first bending stage 78 is bent approximately180 degrees. A large bend such as a bend of approximately 180 degrees,or between around 150-200 degrees, can provide structural support andstrength to the anchor. Such a large bend can also be located at otherpoints in the anchor and at other bending stages. A second bending stage80 is shown used to flare the anchor radially outwardly from the frame20. In a third bending stage 82 the anchor bends in a radially inwarddirection so as to direct the anchor tip 28 towards the opposing anchor22 and position the portion of the anchor between the tip and the thirdbending stage parallel or substantially parallel to the frame 20. Insome embodiments more or fewer bending stages can be used. In addition,the various bending stages can be used to different purposes and toprovide different positions of the anchor than those described above.

The upstream anchor 22 can also have one or more bending stages. Theanchor 22 has a base 84 where the strut of the third ring 62 connects tothe longitudinal strut 56. A first bending stage 86 of the anchor 22 canbe located at the base to move the anchor 22 radially outwardly fromframe 20. A second bending stage 88 can further move the anchor 22radially outwardly from frame 20. In this way, the anchor 22 can be bentin a gradual manner away from the frame 20. In some embodiments, onebending stage can be used to move the anchor 22 away from the frame. Theanchor 22 can also include a large bend similar to the approximately 180degree bend in the first bending stage 78 of anchor 24. Finally, anchor22 is also shown with a third bending stage 90. The third bending stage90 can direct the anchor tip 26 towards the opposing anchor 24 andposition the tip parallel or substantially parallel to the frame 20.

The transition portion 40 can also include one or more bending stages,such as bending stages 92, 94 shown in FIG. 4.

Notably, in this embodiment the native annulus which is intended to begripped between the anchor tips 26, 28 will be engaged by theforeshortening zone 54 of the frame 20, and will not engage thetransition portion 40 of the frame 20. Rather, in a mitral placement,the upstream 38 and transition 40 portions of the replacement valve 10will not necessarily be disposed within the annulus but mostly orentirely in the atrium.

In the embodiment illustrated in connection with FIGS. 1-5, the valvebody 30 is a two-layer valve comprising an outer valve skirt 33 andinner leaflets 32 (see FIGS. 2 and 3A). The outer valve skirt 33 isdisposed between the leaflets 32 and the frame 20. It is to beunderstood, however, that in other embodiments, a single-layer valvebody 30 not having an outer valve skirt 33 may be employed.

With particular reference next to FIG. 6, an embodiment of conical valveleaflet 32 is shown. This figure shows one embodiment of a pattern forcutting the leaflets 32 from a flat, tissue material such aspericardium. Preferably, upstream portions of the leaflets are generallycurved and commissures are disposed along downstream side edges of theleaflets. The curvature and size of the pattern cuts, and particularlythe curvature of the side edges, is chosen so that the valve fits withinthe generally conical shape defined by the frame 20. In the illustratedembodiment, the side edges at and adjacent the downstream end are angledrelative to a longitudinal axis of the valve. As such, the valve asdefined by the leaflets 32 has an outflow diameter that is greater thanits inflow diameter. In addition, as discussed previously, the leafletscan extend between different diameter sections of the valve body, thusthe leaflets are generally positioned at a smaller diameter at theupstream end than at the downstream end. FIG. 6A shows anotherembodiment of a conical leaflet pattern 32′.

In the illustrated embodiments, the outer valve skirt 33 is attached tothe frame 20 and the leaflets 32 are attached to the outer valve skirt33. Preferably, the outer valve skirt 33 is also formed of a pericardiumtissue similar to the leaflets 32. The outer valve skirt 33 can beconstructed in multiple different ways. For example, with reference nextto FIGS. 7 and 8, embodiments show that an outer valve skirt 33, 33′ canbe made by cutting multiple pieces of flat tissue material and sewingthe tissue together to form the outer valve skirt with the flaredtransition portion. In FIG. 7, a generally rectangular piece 68 makes upthe constant-diameter upstream portion 38 of the outer valve skirt 33,and three or more curving pieces 70 that can be sewn together toapproximate the shape of the flared transition portion 40 are cut, sewntogether, and sewn to the downstream end of the upstream portion 38 toconstruct the outer valve skirt 33.

In FIG. 8, multiple pieces 72, each having a constant-width upstreamportion, an expanding-width transition portion, and a constant-widthdownstream portion can be employed to form an outer valve skirt 33′. Inthe illustrated embodiment, three such pieces are shown and can be sewntogether to create the flared valve skirt. However, it is to beunderstood that in other embodiments, six, nine, or 12 pieces, or evenother numbers of pieces can be employed to construct a flared outervalve skirt 33′.

With reference next to FIG. 9, an embodiment of a pattern for forming anouter valve skirt 33″ out of a single piece of flat tissue is shown. Inthis embodiment, the downstream end is generally contiguous, butcavities are cut from an upstream end down to a point adjacent thedownstream end. Upstream portions of the cavities are generally constantin width so as to approximate the upstream portion of the outer valveskirt 33″, and transition portions of the pattern progressively reducein width until forming a point so as to correspond to the transitionportion. In constructing the outer valve skirt 33″, the opposing edgesof the cavities are sewn together so that the valve skirt takes on theflared shape generally corresponding to the frame 20. In the illustratedembodiment, six cavities are used. However, in other embodiments, moreor less cavities such as three, nine, or 12, can be employed.

Preferably, the outer valve skirt 33 is constructed of a tissue that isflexible, but not particularly expansive and stretchy. As such, in theillustrated embodiments, the outer valve skirt 33 extends through thenon-foreshortening zone 52 of the frame 20, but does not extend into theforeshortening zone 54 of the frame 20. However, in other embodiments, aportion of the outer valve skirt 33 may extend into the foreshorteningzone 54.

Referring back to FIGS. 1 and 2, in a preferred embodiment a downstreamend of the outer valve skirt 33 is sewn to a connection skirt 50. Theconnection skirt 50 can be made of knit polyester or another stretchablefabric. The connection skirt 50 can be made to move with theforeshortening portion 54 of the frame 20.

With additional reference next to FIG. 10, one embodiment of a flatpattern for a connection skirt 50 is illustrated. In this embodiment, anupstream edge of the connection skirt 50 is generally straight so as tocorrespond to the downstream edge of the outer valve skirt 33 andcontribute to an advantageous seam structure. A downstream end of theconnection skirt, 50 however, undulates. Preferably, the undulations arepatterned to generally correspond to undulations of struts in theforeshortening zone 24 of the frame 20, such as struts of the fifth ring66. The undulations can match the curvature of the struts, and theconnection skirt 50 is sewn along the edges of its undulations to thecorresponding foreshortening cell struts, as shown in FIGS. 1 and 2. Itis to be understood that other configurations of connection skirts 50can be employed. For example, a connection skirt 50 can have a generallystraight downstream end or can have undulations that do not correspondwith the end 16 of the frame 20.

With reference next to FIGS. 11 and 12, a schematic side section viewand flat pattern cutout view of a frame 20′ in accordance with anotherembodiment is shown. As with the embodiment in FIGS. 1-5, theillustrated frame 20′ has an upstream portion 38′ of generally constantdiameter, a transition portion 40′ of expanding diameter and adownstream or annulus-engagement portion 42′ of generally constantdiameter, which diameter is greater than the upstream portion diameter.In this embodiment, longitudinal struts 56′ extend distally beyond thetransition portion 40′, and define the upstream anchors 22′. Morespecifically, the longitudinal struts 56′ bend radially outwardly fromthe upstream portion 38′ upstream of the transition portion 40′, andextend downstream beyond the transition portion 40′ so that a downstreamtip of each strut defines an anchor tip 26′. The transition portion 40′in this embodiment is made up of the undulating struts in the third ring62′. The transition portion 40′ also includes two bending stages 92′,94′. Downstream apices in the third ring 62′ have second longitudinalstruts 74 extending therefrom, which connect each downstream apex to anapex of closed foreshortening cells defined by the fourth 64′ and fifth66′ rings.

The anchor 24′ is shown with a base 76′ connected to the fifth ring 66′.The anchor 24′ includes first 78′ and second 80′ bending stages. Thefirst bending stage 78′ positions the anchor 24′ away from the frame 20′and the second bending stage 80′ positions the tip 28′. The anchor 22′also has first 86′ and second 88′ bending stages. The first bendingstage 86′ is located at and near the base 84′ and positions the anchor22′ away from frame 20′. The second bending stage 88′ positions theanchor tip 26′ towards the opposing anchor 24′ and positions the tipparallel or substantially parallel to the frame 20′.

In the frame 20′ embodiment of FIGS. 11 and 12, since the third ring 62′is attached to the longitudinal struts 56′ only at the upstream apices,at least some foreshortening can be anticipated in the transitionportion 40′ due to expansion of the third ring struts. In a preferredembodiment, a greater proportion of foreshortening takes place in theclosed foreshortening cells of the downstream fourth 64′ and fifth 66′rings than in the third ring 62′. In some embodiments, a greaterproportion of the outer valve skirt or all of the outer valve skirt canbe constructed of flexible fabric so that the outer valve skirt canaccommodate and move with the foreshortening third ring 62′, while theleaflets can continue to be made of a generally nonelastic material suchas pericardium. In further embodiments, a pericardium outer valve skirtcan be relatively-loosely stitched or otherwise attached to a connectionskirt and the frame 20′ along, for example, the second longitudinalstruts 74 so that during the radial expansion process, the distal end ofthe outer valve skirt can move relative to the frame 20′ so that theouter valve skirt and the leaflets maintain optimal geometry andplacement as the frame length changes. In still further embodiments, thestruts of a third ring 62′ can be configured so that any foreshorteningduring radial expansion is sufficiently minor or small so as to notsubstantially affect tissue-based valve members such as the outer valveskirt and/or leaflets.

FIG. 13 shows yet another embodiment of a frame 20″. The frame 20″ has asubstantially constant inner diameter, such that the diameter issubstantially the same at the two opposing ends 14″ and 16″. Thisembodiment employs longitudinal struts 56″ in the non-foreshorteningportion 52″ and first 58″ and second 60″ rings of expansile strutsconnected to the longitudinal struts 56″. The second rings 60″ flareradially outwardly as part of the anchors 22″. The foreshortening zone54″ has two rows of closed foreshortening cells made by third 62″,fourth 64″ and fifth 66″ rings. The downstream anchors 24″ extend frompoints adjacent the downstream end 16″ of the frame 20″, but portions ofsome of the foreshortening cells are downstream of the anchor bases. Inthe illustrated embodiment, the downstream anchors are longer than theupstream anchors.

Referring to FIG. 14, a schematic side view of a frame 20′″ is shown. Asmentioned previously, the frame 20 has a non-foreshortening zone 52′″and a foreshortening zone 54′″. Longitudinal struts 56′″ span all orpart of the length of the non-foreshortening zone 52′″. Distal ordownstream portions of the longitudinal struts 56′″ make up all or partof the transition portion 40′″, in which the struts 56′″ bend at bendingstage 92′″ so as to flare radially outwardly and then bend again atbending stage 94′″ so as to stop expanding in radius and attach to theforeshortening zone 54′″ of the frame 20′″. As such, the frame 20′″ isgenerally divided into an upstream portion 38′″ made up of the firstdiameter, a transition portion 40′″ at which the diameter is expanding,and a downstream portion 42′″ which includes the foreshortening zone54′″ and which is adapted to engage the native valve annulus.

One, two, three, or more rings made up of undulating struts can beconnected to the longitudinal struts 56′″ in the non-foreshortening zone52′″. One, two, three, or more rings made up of undulating struts canalso be used to form the foreshortening zone 54′″.

Downstream anchors 24′″ can extend from a portion of the downstreamportion 42′″ or foreshortening portion 54′″ as shown. The downstreamanchors 24′″ are bent down or bent out from the frame 20′″ and flaredradially out from the frame 20′″. Anchor 24′″ is shown with a base 76′″connected to the frame 20′″. The anchor 24′″ includes first 78′″, second80′″ and third 82′″ bending stages. The first bending stage 78′″ is aradially inward bend. The inward bend can be between about 5-30 degrees,for example. The second bending stage 80′″ can have a large bend, suchas an approximately 180 degree radially outwardly extending bend, orbetween around 150-200 degrees, as has been described. After the secondstage bend the anchor extends in an upstream and radially outwarddirection. The first 78′″ and second 80′″ bending stages can positionthe anchor 24′″ away from the frame 20′″. The third bending stage 82′″can position the tip 28′″, such as to position the tip 28′″ to opposethe anchor tip 26′″ and/or position the tip 28′″ parallel orsubstantially parallel with the frame 20′″. The bend at the thirdbending stage can be, for example, between about 5-30 degrees.

Upstream anchors 22′″ preferably extend from the non-foreshorteningportion 52′″. For example, upstream anchors 22′″ and/or the ring(s) orstruts to which they are attached, are shown extending from thetransition portion 40′″. As can be seen in FIG. 14, the upstream anchors22′″ are flared radially out at a more dramatic angle than is thelongitudinal strut 56′″. As has been mentioned above, the transitionportion 40′″ has a first bending stage 92′″ and a second bending stage94′″ which changes the diameter of the frame 20′″ between the upstreamportion 38′″ and the downstream portion 42′″. The anchor 22′″ also hasfirst 86′″ and second 88′″ bending stages. The first bending stage 86′″is located near or at the base 84′″ and directs the anchor 22′″ awayfrom frame 20′″. The second bending stage 88′″ directs the anchor tip26′″ towards the opposing anchor 24′″ and preferably positions the tipparallel or substantially parallel to the frame 20′″.

In this embodiment, the anchors 22′″ extend from the frame 20′″ at thetransition portion 40′″ rather than at the upstream portion 38′″. Thisallows the anchors 22′″ to have a smaller bend or angle at the firstbending stage 86′″ because some of the desired bend is already providedby the first bending stage 92′″ of the transition at portion 40′″. Forexample, where it is desired to position the anchor 22′″ an angle A₁from the upstream portion, the first bending stage 92′″ of thetransition portion 40′″ can be bent an angle A₂ and then the firstbending stage 86′″ of the anchor 22′″ can be bent the remaining amountto provide the angle A₁. For example, where the anchor 22′″ ispositioned an angle A₁ of approximately 40 degrees from the frame of theupstream portion 38′″, the transition portion can be positioned at anangle A₂ of approximately 20 degrees or 30 degrees and then the anchor22 can be positioned an additional amount from frame at the transitionportion to make up the entire 40 degrees.

In another embodiment, the anchor 22′″ can extend from the upstreamportion of the frame, and can have a first bending stage at which theanchor bends approximately the same as the first bending stage of thetransition portion. The anchor 22′″ can have a second bending stagespaced from the first stage and which directs the anchor 22′″ furtherradially outwardly to the desired angle A₁. The anchor 22′″ has a thirdbending stage to position the anchor tip 26′″.

The upstream anchors 22′″ are bent so as to generally oppose thedownstream anchors 24′″ that extend from the foreshortening zone 54′″. Atip 26′″ of each upstream anchor 22′″ is downstream of the transitionportion 40′″. As such, the anchor tips 26, 28 of the opposing anchors22, 24 can be disposed on opposite sides of the native annulus of aheart valve and used to engage the valve to thereby replace the valvewith a replacement heart valve as has been described herein.

As can also be seen in FIG. 14, the valve body 30′″ can be attached tothe frame 20′″. The valve body 30′″ can be positioned in the upstream38′″, transition 40′″, and/or downstream 42′″ portions. The valve body30′″ can also be positioned in both the foreshortening 54′″ and thenon-foreshortening 52′″ zones. An example leaflet 32′″ is alsoillustrated. In this embodiment, the leaflet 32′″ is within thetransition portion 40′″ and the downstream portion 42′″ but is notwithin the upstream portion 38′″.

In some embodiments, the implant can be delivered via a transvenous,transseptal, or an antegrade approach.

FIGS. 15-19 are photographs filed in U.S. Provisional Application No.61/357,048, filed on Jun. 21, 2010, which has been incorporated hereinby reference. These images are of post-implant examination which showedengagement of an implant with native leaflets and annulus. Referringnext to FIGS. 15-19, an embodiment of a valve 10″″ having a frame 20″″and valve body 30″″ is shown deployed within a native mitral valve.FIGS. 15-17 are shown from within the left ventricle and FIGS. 18 and 19are shown from within the left atrium.

With reference first to FIGS. 15-17, the downstream anchors 24″ canextend around the native mitral valve leaflets. As shown, the downstreamanchors 24″ extend between chordae tendineae coupling the native mitralvalve leaflet and papillary heads of papillary muscle. The tips 28″ ofthe downstream anchors 24″ can engage the native mitral valve annulus.As shown in the illustrated embodiment, in some instances tips 28″ ofthe downstream anchors 24″ can engage the fibrous trigones of the nativemitral valve. With reference next to FIGS. 18 and 19, the tips 26″ ofthe upstream anchors 22″ can engage the native mitral valve annulus.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In addition, while a number of variations of the invention havebeen shown and described in detail, other modifications, which arewithin the scope of this invention, will be readily apparent to those ofskill in the art based upon this disclosure. It is also contemplatedthat various combinations or subcombinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the invention. For example, the frame shown in FIG. 13 caninclude a transition portion as shown in FIGS. 1 and 2, FIGS. 11-12, orFIG. 14. In addition, the down stream anchors of FIG. 1 can be spacedfrom the downstream end of the frame as shown in FIG. 13. As anotherexample, the anchors of the embodiments depicted in FIGS. 1, 2, 4, 11and 13 can employ the bend stages shown in FIG. 14 or vice versa.Accordingly, it should be understood that various features and aspectsof the disclosed embodiments can be combined with or substituted for oneanother in order to form varying modes of the disclosed invention. Thus,it is intended that the scope of the present invention herein disclosedshould not be limited by the particular disclosed embodiments describedabove, but should be determined only by a fair reading of the claimsthat follow.

What is claimed is:
 1. A prosthesis configured to be deployed within anative mitral valve, the prosthesis comprising: an expandable frameconfigured to radially expand and collapse for deployment within thenative mitral valve, the expandable frame comprising a proximal portionhaving an inflow end, a distal portion having an outflow end and alongitudinal axis extending from the inflow end to the outflow end, theinflow end configured to be positioned upstream of the outflow end whenthe prosthesis is deployed within the native mitral valve, across-sectional dimension perpendicular to the longitudinal axis of theoutflow end being greater than a cross-sectional dimension perpendicularto the longitudinal axis of the inflow end when the expandable frame isin an expanded configuration; a valve body positioned within a lumen ofthe expandable frame; and one or more distal anchors extending from theoutflow end of the expandable frame, wherein the distal anchors aresized such that, when the prosthesis is expanded and deployed within thenative mitral valve: at least one of the distal anchors is positionedradially outwardly from the expandable frame; at least one of the distalanchors extends between chordae tendineae of the native mitral valve; atleast one of the distal anchors contact tissue on a ventricular side ofthe native mitral valve; and tips of the one or more distal anchorsextend substantially parallel to the longitudinal axis of the expandableframe.
 2. The prosthesis of claim 1, wherein the prosthesis furthercomprises a proximal anchoring portion sized to contact tissue on anatrial side of the native mitral valve when the prosthesis is deployedwithin the native mitral valve, an end of the proximal anchoring portionbeing positioned radially outwardly from the expandable frame when theexpandable frame is in the expanded configuration.
 3. The prosthesis ofclaim 2, wherein the proximal anchoring portion comprises a plurality offree apices each connected to the expandable frame at a first base andat a second base, the first and the second bases located distal of theinflow end of the expandable frame.
 4. The prosthesis of claim 2,wherein each distal anchor extends from a portion of the expandableframe having a greater cross-sectional dimension than a portion of theexpandable frame from which the proximal anchoring portion extends. 5.The prosthesis of claim 1, wherein the distal anchors are sized suchthat, when the prosthesis is expanded and deployed within the nativemitral valve, at least a first of the distal anchors contacts a firstfibrous trigone of the native mitral valve.
 6. The prosthesis of claim5, wherein the prosthesis is sized such that, when the prosthesis isexpanded and deployed within the native mitral valve, a native leafletof the native mitral valve is positioned between at least the firstdistal anchor and the expandable frame.
 7. The prosthesis of claim 5,wherein the distal anchors are sized such that, when the prosthesis isexpanded and deployed within the native mitral valve, at least a secondof the distal anchors contacts the native mitral valve annulus.
 8. Theprosthesis of claim 5, wherein the distal anchors are sized such that,when the prosthesis is expanded and deployed within the native mitralvalve, at least a second of the distal anchors contacts a second fibroustrigone of the native mitral valve.
 9. The prosthesis of claim 1,wherein the expandable frame further comprises an engagement zone, andwherein the engagement zone is sized such that, when the prosthesis isexpanded and deployed within the native mitral valve, the engagementzone engages the native mitral valve annulus.
 10. The prosthesis ofclaim 9, wherein the engagement zone is positioned between ends of thedistal anchors and an end of a proximal anchoring portion.
 11. Theprosthesis of claim 10, wherein the engagement zone is sized such that,when the prosthesis is expanded, a cross-sectional dimension of theengagement zone is greater than a cross-sectional dimension of aproximal end of the expandable frame.
 12. The prosthesis of claim 10,wherein the valve body comprises an inflow end and an outflow end andwherein the engagement zone is sized such that, when the prosthesis isexpanded and deployed within the native mitral valve, a cross-sectionaldimension of the engagement zone is greater than a cross-sectionaldimension of the inflow end of the valve body.
 13. The prosthesis ofclaim 1, wherein the valve body comprises a plurality of valve leaflets.14. The prosthesis of claim 13, wherein the prosthesis comprises aplurality of commissures disposed along downstream side edges of thevalve leaflets.
 15. The prosthesis of claim 13, wherein the valve bodycomprises three leaflets.
 16. The prosthesis of claim 13, wherein theplurality of valve leaflets are configured to open to allow flow in afirst direction from an atrium to a ventricle and engage one another soas to close and not allow flow in a second direction opposite the firstdirection.
 17. The prosthesis of claim 1, wherein each of the one ormore distal anchors is formed by a single strut.
 18. The prosthesis ofclaim 1, wherein the tips of the one or more distal anchors are enlargedrelative to a remainder of the one or more distal anchors to increase asurface area of the tips in contact with the tissue when the prosthesisis expanded and deployed within the native mitral valve.
 19. Aprosthesis configured to be deployed within a native mitral valve, theprosthesis comprising: an expandable frame configured to radially expandand collapse for deployment within the native mitral valve, theexpandable frame comprising a proximal portion having an inflow end, adistal portion having an outflow end, a transition portion between thedistal portion and the proximal portion, and a longitudinal axisextending from the inflow end to the outflow end, the inflow endconfigured to be positioned upstream of the outflow end when theprosthesis is deployed within the native mitral valve, a cross-sectionaldimension perpendicular to the longitudinal axis of the outflow endbeing greater than a cross-sectional dimension perpendicular to thelongitudinal axis of the inflow end when the expandable frame is in anexpanded configuration, wherein the proximal portion and the distalportion have a constant cross-sectional diameter perpendicular to thelongitudinal axis, and wherein the transition portion decreases incross-sectional diameter perpendicular to the longitudinal axis movingfrom the distal portion to the proximal portion; a valve body positionedwithin a lumen of the expandable frame, the valve body comprising aproximal end, a distal end, wherein a diameter at the distal end isgreater than a diameter at the proximal end, and a plurality of valveleaflets; one or more proximal anchors each connected to the expandableframe such that when the expandable frame is in the expandedconfiguration an end of each of the one or more proximal anchors ispositioned radially outward from the frame, wherein the one or moreproximal anchors are configured to contact tissue on an atrial side ofthe native mitral valve; one or more distal anchors extending from theoutflow end of the expandable frame, wherein the distal anchors aresized such that, when the prosthesis is expanded and deployed within thenative mitral valve: at least one of the distal anchors is positionedradially outwardly from the expandable frame; at least one of the distalanchors extends between chordae tendineae of the native mitral valve; atleast one of the distal anchors contact tissue on a ventricular side ofthe native mitral valve; and tips of the one or more distal anchorsextend parallel to the longitudinal axis of the expandable frame.